The purpose of the proposed research is to investigate factors which influence the specificity of cardiovascular responses acquired under operant conditioning and exteroceptive feedback procedures. Two series of experiments, one on rats and the other on humans, are described. The animal experiments are designed to investigate the differential effects of three aspects of a shock-avoidance procedure on changes in a broad spectrum of activities (cardiovascular, somatmotor, and respiratory), all related to the movement process. These factors are contingency (whether heart rate or somatomotor changes are identified as the avoidance response), Somaomotor Response Cost (whether ambulation requires the expenditure of high or low levels of energy) and the Conditioning Environment (whether the reinforcement contingencies are applied in an open field situation where rats tend to "freeze" or in a running wheel situation where they tend to move). The human experiments are designed to investigate the relationship between the discriminability of cardiovascular processes and their amenability to specific instructional control. As in the animal experiments, a broad spectrum of activities will be examined for differential effects due to various procedural manipulations. The experimental program is designed to permit the assessment of various training procedures involving instructions and various forms of exteroceptive feedback of performance on both the discrimination and control of heart rate. Discrimination of cardiovascular activities will be assessed employing a procedure which permits the study of interoceptive discrimination in intact humans.